export function encodeUTF8(s) {
	var i, r = [],
		c, x;
	for (i = 0; i < s.length; i++)
		if ((c = s.charCodeAt(i)) < 0x80) r.push(c);
		else if (c < 0x800) r.push(0xC0 + (c >> 6 & 0x1F), 0x80 + (c & 0x3F));
	else {
		if ((x = c ^ 0xD800) >> 10 == 0) //对四字节UTF-16转换为Unicode
			c = (x << 10) + (s.charCodeAt(++i) ^ 0xDC00) + 0x10000,
			r.push(0xF0 + (c >> 18 & 0x7), 0x80 + (c >> 12 & 0x3F));
		else r.push(0xE0 + (c >> 12 & 0xF));
		r.push(0x80 + (c >> 6 & 0x3F), 0x80 + (c & 0x3F));
	};
	return r;
}

// 字符串加密成 hex 字符串
export function sha1(s) {
	var data = new Uint8Array(encodeUTF8(s))
	var i, j, t;
	var l = ((data.length + 8) >>> 6 << 4) + 16,
		s = new Uint8Array(l << 2);
	s.set(new Uint8Array(data.buffer)), s = new Uint32Array(s.buffer);
	for (t = new DataView(s.buffer), i = 0; i < l; i++) s[i] = t.getUint32(i << 2);
	s[data.length >> 2] |= 0x80 << (24 - (data.length & 3) * 8);
	s[l - 1] = data.length << 3;
	var w = [],
		f = [
			function() {
				return m[1] & m[2] | ~m[1] & m[3];
			},
			function() {
				return m[1] ^ m[2] ^ m[3];
			},
			function() {
				return m[1] & m[2] | m[1] & m[3] | m[2] & m[3];
			},
			function() {
				return m[1] ^ m[2] ^ m[3];
			}
		],
		rol = function(n, c) {
			return n << c | n >>> (32 - c);
		},
		k = [1518500249, 1859775393, -1894007588, -899497514],
		m = [1732584193, -271733879, null, null, -1009589776];
	m[2] = ~m[0], m[3] = ~m[1];
	for (i = 0; i < s.length; i += 16) {
		var o = m.slice(0);
		for (j = 0; j < 80; j++)
			w[j] = j < 16 ? s[i + j] : rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1),
			t = rol(m[0], 5) + f[j / 20 | 0]() + m[4] + w[j] + k[j / 20 | 0] | 0,
			m[1] = rol(m[1], 30), m.pop(), m.unshift(t);
		for (j = 0; j < 5; j++) m[j] = m[j] + o[j] | 0;
	};
	t = new DataView(new Uint32Array(m).buffer);
	for (var i = 0; i < 5; i++) m[i] = t.getUint32(i << 2);

	var hex = Array.prototype.map.call(new Uint8Array(new Uint32Array(m).buffer), function(e) {
		return (e < 16 ? "0" : "") + e.toString(16);
	}).join("");
	return hex;
}
